The prominence of bollards has dramatically increased in the past decade as a result of heightened fears about security. They are a basic, practical, and cost-effective means of erecting anti-ram perimeter defense without developing a visual sense of a fortified bunker. Bollards are popular for traffic direction and control, and in purely decorative applications. However, buy steel bollards can serve many characteristics beyond security. They can be used purely aesthetic purposes, functioning as landscaping elements. Bollards can create visible boundaries of a property, or separate areas within sites. They can control traffic and they are often set up to allow pedestrian access while preventing entry of vehicles.
Removable and retractable bollards can allow different amounts of access restriction for a variety of circumstances. They frequently tell us where we can and cannot drive, park, bike, or walk, protect us from crime, shield vehicles and property from accidents, and add aesthetic features to the building exteriors and surrounding areas. Bollards can incorporate other functions including lighting, security cameras, bicycle parking or perhaps seating. Decorative bollards are produced in a selection of patterns to harmonize with a variety of architectural styles. The prevalence of the most common kind of security bollard, the concrete-filled steel pipe, has encouraged the manufacturing of decorative bollards made to fit as covers over standard steel pipe sizes, adding pleasing form towards the required function.
What Exactly Is A Bollard?
A bollard is actually a short vertical post. Early bollards were for mooring large ships at dock, and they are still being used today. A normal marine bollard is manufactured in cast iron or steel and shaped somewhat such as a mushroom; the enlarged top is designed to prevent mooring ropes from slipping off.
Today, the word bollard also describes many different structures applied to streets, around buildings, as well as in landscaping. According to legend, the very first street bollards were actually cannons – sometimes said to be captured enemy weapons – planted in the earth as boundary posts and town markers. Once the supply of former cannons was utilized up, similarly shaped iron castings were designed to match the same functions. Bollards have since evolved into many varieties which can be widely employed on roads, particularly in urban areas, along with outside supermarkets, restaurants, hotels, shops, government buildings and stadiums.
The most frequent kind of bollard is fixed. The simplest is surely an unaesthetic steel post, about 914 to 1219 mm (36 to 48 in.) above-grade. Specially manufactured bollards include not only simple posts, but additionally a multitude of decorative designs. Some feature square or rectangular cross-sections, but most are cylindrical, sometimes having a domed, angled, or flat cap. They come in a variety of metallic, painted, and sturdy powder coat finishes.
Removable bollards are used where the need to limit access or direct traffic changes occasionally. Both retractable and fold-down styles are employed where selective entry is frequently needed, and they are designed and so the bollard can easily be collapsed to ground level and quickly re-erected. Both retractable units may be manually operated or automated with hydraulic movements. Movable bollards are large, heavy objects – frequently stone or concrete – that depend on how much they weigh rather than structural anchoring to stay in place. They are designed to be moved rarely, and after that just with heavy machinery for instance a fork-lift.
Bollards generally fall under three kinds of applications:
Decorative Bollards – decorative bollards for architectural and/or landscaping highlights;
Traffic and Safety Bollards – bollards that offer asset and pedestrian safety, as well as traffic direction; and
Security Bollards and Post Covers – decorative, impact-resistant bollard enhancements
Some bollards are intended purely to get an ornament. As standalone architectural or landscaping features, they could border, divide, or define a place. They can also be accents, sentries, or supporting players to larger, more dramatic architectural gesture.
Decorative bollards are made to harmonize with both traditional and contemporary architectural styles. The second lean toward visual simplicity – often straight-sided posts with one or more reveals close to the top. Styles created to match various historic periods usually have more elaborate shapes and surface details. Included in this are flutes, bands, scrolls along with other ornamentation.The post-top is really a distinctive feature; traditional bollard design often includes elaborate decorative finials, whereas contemporary versions frequently include a simple rounded or slanted top to discourage passersby from leaving trash or utilizing them for impromptu seating. On the other hand, these are sometimes made flat and broad specifically to encourage seating. Common decorative bollard materials include iron, aluminum, stainless, and concrete.
Ornamental designs with elaborate detail are usually manufactured from iron or aluminum casting. Aluminum bollards are desirable for applications where weight is a concern, for instance a removable bollard. Aluminum units tend to be slightly more expensive than iron. For applications in which a decorative bollard could be subjected to destructive impact, ductile iron is actually a safer choice than more brittle metals, as force will deform the metal rather than shatter and transforming it into possible hazardous flying projectiles.
Iron and aluminum bollards are usually manufactured by sand-casting – a regular foundry technique that is certainly economical and well-fitted to objects this size. However, sand-cast objects frequently bear surface irregularities that have a tendency to leave the finished product less popular with the eye. If high-finish consistency is desired, seek a manufacturer that will machine 100% of the surface after casting to produce units having a uniform surface for max visual appeal.
Finish is a crucial consideration in a decorative bollard, from functional as well as aesthetic standpoints. Bollards are, by their nature, susceptible to being scratched or nicked by pedestrians and vehicles. Those located near roadways are exposed to a fairly aggressive environment; petrochemical residues and splashes of diluted road de-icing salts may compromise some painted finishes. Factory-applied powder coating – which can be available on iron, aluminum, and steel – is an especially durable kind of painted finish. The application process builds a coating with very consistent coverage. During coating, any bare metal tends to attract the powder, eliminating pinholes in coverage. The baking procedure that completes the finish gives it additional toughness and abuse resistance.
In applications where greater physical abuse is predictable, plastic bollards manufactured from aluminum may be a better choice than iron. If the finish coat is damaged, aluminum oxidizes to a color that is generally more acceptable than the red rust produced by iron. Aluminum and stainless steel are also offered in a quantity of bare metal finishes. Functionality can be added to the otherwise decorative bollard. As an example, common choice is the chain eye – linking several bollards with chain, developing a simple traffic direction system. A big metal loop or arm on the side of the post allows parking and locking of bicycles, a progressively popular choice as increasing numbers of people seek alternative green transportation. Bollards could also contain lighting units or security devices, like motion sensors or cameras.
Traffic and Safety Bollards
The most common bollard applications are traffic direction and control, together with safety and security. The first function is achieved from the visual presence from the bollards, and to some degree by impact resistance, although, within these applications visual deterrence is the primary function. Security and safety applications depend on higher degrees of impact resistance. The key difference between the 2 is safety designs are concerned with stopping accidental breach of a defined space, whereas security is all about stopping intentional ramming.
Closely spaced lines of bollards can form a traffic filter, separating motor vehicles from pedestrians and bicycles. Placing the posts with 1 m (3 ft) of clearance between the two, for example, allows easy passage for humans and human-powered vehicles – including wheelchairs or shopping carts – but prevents the passage of cars. Such installations tend to be seen facing zcvjbu parking area entrance to a store, and also at the mouths of streets changed into outdoor malls or ‘walk streets’. In designing bollard installations for a site, care should be taken to avoid locating them where they will likely turn into a navigational hazard to authorized vehicles or cyclists.
Some applications for traffic guidance depend on the cooperation of drivers and pedestrians and never require impact resistance. A collection of bollards linked with a chain presents a visual cue never to cross the boundary, although it may be easy enough to get a pedestrian to visit over or beneath the chain should they choose. Bollards designed to direct traffic are often created to fold, deflect, or break away on impact.
Adding greater collision resistance allows a bollard to enforce traffic restrictions as opposed to merely suggesting them. Plain pipe bollards are usually placed at the corners of buildings, or flanking lamp-posts, public phones, fire hydrants, gas pipes as well as other installations that should be protected against accidental contact. A bollard at the fringe of a roadway prevents cars from over-running sidewalks and harming pedestrians. Bell-shaped bollards can in fact redirect a car back onto the roadway when its wheels hit the bollard’s sloped sides.
They are employed where U-turns and tight-radius turns are frequent. This type of usage is particularly common at corners where vehicle drivers often misestimate turns, and pedestrians are specifically near to the roadbed waiting to cross. In a few cities, automatically retractable impact-resistant bollards are installed to control the flow of traffic into an intersection. Internet videos of ‘bollard runners’ graphically demonstrate the effectiveness of also a low post at stopping cars.